It has been proposed before to utilize various devices to improve the securement of a coupling to a hose. An example of one such device is disclosed in U.S. Pat. No. 589,216 in which a sheet metal band having diagonal edges and prongs is disposed between a coupling and the inner wall of the bore of a bore. The band is designed in such a manner that the diagonal edges substantially close when the band is secured to the outer surface of the coupling and the prongs are adapted to engage the inner wall of the hose bore when the coupling is inserted into the bore of the hose. The band, however, relies solely on the barbs as a means of securing the hose to the coupling and does not provide for a portion of the wall of the hose to flow between its diagonal edges nor does it have one or more longitudinally extending primary elongate openings in its wall disposed in a uniform array about its circumference into which the wall of the hose will extend to provide a circumferentially uniform longitudinally gripping engagement with the wall of the hose. Another example of a device used to improve the securement of a coupling to a hose is disclosed in U.S. Pat. No. 2,121,624 in which a wire helix is disposed between the shell of a coupling and the outer surface of a hose to provide a flexible conduit connection. The use of the helically coiled wire disclosed in U.S. Pat. No. 2,121,624 has the disadvantage that the inner surface of the shell is required to be threaded in order to receive and position the helical coils of the wire in a uniform manner in order to prevent the coil from warping when compressed between the hose and the shell of the coupling. It is an advantage of the insert of the present invention that it can be used without subjecting the inner surface of the shell of the coupling with which it is used to a costly machining operation such as threading. A solution to the problem of warp associated with helically coiled wire used in conjunction with hose couplings is disclosed by the inventor of the present invention in U.S. Pat. No. 4,099,748 in which circumferentially spaced longitudinal members are used to secure an axial spaced relationship between at least a portion of the coils. Although the helically coiled wires disclosed in U.S. Pat. Nos. 2,121,624 and 4,099,748 may be used to their respective advantage, their use generally requires, as described above, either subjecting the inner surface of the coupling shell to a costly threading operation or in having to provide means of securing a spaced re-relationship between the coils. A further disadvantage associated with using helically coiled wire to improve the securement between a coupling and a hose is that coils required to fit within the annular space available between the inner surface of the shell and the outer surface of the hose may not be commercially available and, as a result thereof, the user may incur additional costs in order to have it specially made to meet the requirements of a particular application. In contrast, the insert of the present invention can be made in a relatively simple forming operation as hereinafter described. A further example of a device used to improve the securement of a coupling to a hose can be found in U.S. Pat. No. 2,449,916 in which a tapered, split, internal compression ring having one or more circumferentially extending elongated openings is disclosed. The circumferential extending axis of the ring openings are normal to the longitudinal central axis of the ring and substantially normal to the longitudinally extending axis of the split in the wall of the ring. Although the tapered split ring disclosed in U.S. Pat. No. 2,449,916 may be used to impart a circumferential gripping engagement with the wall of the hose with which it is used, it does not engage the wall of the hose in the improved manner of the insert of the present invention whereby the wall of the hose is gripped in a longitudinally extending substantially uniform manner about the circumference of the hose.
The ability to maintain a reliable attachment between a coupling and the end of a hose operating under varying temperature and pressure conditions has been a problem in the past. The above described devices illustrate examples of the variety of means that have been utilized in attempts to improve the manner in which a coupling is secured to the end of a hose. The insert of the present invention has been found to provide a means of improving the securement of a coupling to the end of a hose operating under varying temperature and pressure conditions without having to subject the shell of a coupling to a costly threading operation and without having to rely solely upon prongs and the like to penetrate into the wall of the hose in order to insure the secured relationship between the end of the hose and the coupling. It has further been found that the insert of the present invention can be made in a low cost forming operation and is therefore not subject to the commercial nonavailability of specifically dimensioned coiled springs hereinbefore described. By providing a circumferentially uniform longitudinally extending gripping engagement with portions of the wall of the hose, the insert of the present invention has been found to provide an improved means of maintaining the securement of a coupling to the end of a hose operating under varying temperature and pressure conditions heretofore unknown in the prior art.